ecology test

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  1. examples of abiotic factors
    • sunlight
    • availability of water
    • wind
    • pH
    • mineral content in soil
  2. how do organisms affect abiotic environment
    • Plant roots, lichens, and microorganisms help break down rocks into soil.
    • Dead material and wastes add organic matter and nutrients to soil
    • Roots and organic matter hold soil particles together, reducing erosion.
    • Transpiration from forests increases humidity, forming clouds and promoting rainfall.
  3. define biomass
    • total quantity of living matter
    • declines at higher trophic levels
  4. define productivity
    • rate at which new biomass forms
    • declines with each trophic level, highest among primary producers
  5. define ecosystem
    An array of organisms and their physical environment, all of which interact through a one-way flow of energy and a cycling of materials
  6. what information is used in an ecological pyramid?
    • demonstrates relationship between energy and trophic levels in an ecosystem
    • number of individuals at a given trophic level (pyramid of numbers)
    • amount of biomass at a given trophic level (pyramid of biomass)
    • amount of energy at a given trophic level (pyramid of energy)
  7. main problem with pyramid of biomass
    can make a trophic level look like it contains more energy than it actually does
  8. pyramid of energy
    • most useful
    • measures number of calories per trophic level
    • uses 10% rule
  9. define limiting factors
    conditions that regulate the number of organisms that can live in an area
  10. define population distribution
    • pattern of dispersal of individuals in an area
    • (uniform, random, clumped)
  11. define exponential growth
    numbers of members grow rapidly, often when limits are removed
  12. define logistic growth
    growth slows, curving to a stable maximum
  13. define carrying capacity
    largest population of a species that the environment can support
  14. what is a boom-and-bust cycle
    • exponential growth leads to overshoot (numbers go beyond carrying capacity)
    • population crashes
  15. what are density-dependent factors
    • the number of organisms present influences the effect of the factor
    • -predation
    • -competition
  16. define competitive exclusion principile
    No two species can occupy the same niche at the same time.
  17. types of symbiosis
    • parasitism (1 benefits, 1 is harmed)
    • commensalism (1 is benefited, 1 is not affected)
    • mutualism (both benefit)
  18. how does carbon move through the biosphere
    cell respiration and carbon fixation
  19. describe tundra
    • dry
    • cold
    • cannot support trees
    • shallow, frozen soil
  20. describe taiga
    • fairly dry
    • cold winters
    • shallow, acidic soil
    • conifers and mosses
  21. describe temperate deciduous forest
    • 80-140 cm rain per year
    • hot summers, cold winters
    • deciduous trees lose leaves in the fall
  22. describe grasslands
    • moderate temperatures, can vary
    • 25-75 cm/year
    • rich soil
    • too dry for trees
    • -mostly grasses, fire important
  23. describe deserts
    • arid: little/no precipitation
    • hot day, cold night
    • vegetation adapted to conserve water
  24. describe tropical rain forest
    • 68-77 degrees F
    • wet all year
    • acidic, nutrient-poor soil
    • -rapid decomposition
    • plants have competition for light
  25. 3 zones in a lake
    • littoral zone: close to shore, photosynthesis occurs and producers are found
    • limnetic zone: layer of open water where photosynthesis can occur
    • profundal zone: no light, mostly decomposers
  26. define neritic zone
    • shallow water over continental shelf
    • past shelf is oceanic zone
  27. pelagic zone
    open water not associated with the seafloor
  28. benthic zone
    region of seafloor that receives some light
  29. abyssal zone
    area of benthic zone where light does not penetrate
  30. what are estuaries
    where freshwater streams or rivers flow into the ocean
  31. define invasive species
    an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health
  32. define alien species
    any species, including its seeds, eggs, spores, or other biological material capable of propagating that species, that is not native to a particular ecosystem
  33. describe kudzu
    • Scientific name: Pueraria montana
    • Native To: Asia
    • Date of U.S. Introduction: Late 1800s
    • Means of Introduction: Introduced as an ornamental vine and for erosion control
    • grows rapidly, covering anything in its path
  34. describe purple loosestrife
    • Scientific name: Lythrum salicaria
    • Native To: Eurasia
    • Date of U.S. Introduction: Early 1800s
    • Means of Introduction: As an
    • ornamental
    • takes over floodplains and freshwater marshes
  35. describe zebra mussels
    • Scientific name: Dreissena polymorpha
    • Native To: Eurasia
    • Date of U.S. Introduction: 1988
    • Means of Introduction: Ballast water
  36. zebra mussels economic impact
    • Negative impact upon sport fishing
    • –Can interfere with cooling systems of boats
    • –Cause problems with buoys and lead to premature deterioration of docks
    • Clog water intake pipes that serve homes and
    • entire municipalities, causing millions of dollars in damage.
    • Zebra mussels can produce lacerations of the
    • feet of swimmers
  37. describe west nile virus
    • Scientific name: Flavivirus
    • Native To: Africa, Western Asia and Middle East
    • Date of U.S. Introduction: First cases described in 1999
    • Means of Introduction: Unknown
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ecology test
biology exam
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